Garlic pungency may explain heart benefits

Fundamental research suggests the manner in which garlic inspires
gastric pain could also be the way it brings heart benefits.

Garlic, like leeks and onions, belongs to the plant genus
Allium​, and is known for its pungency and spiciness.

In recent years, science has tentatively linked consumption of
garlic to having a beneficial impact on the heart, including
reducing blood pressure and cholesterol. But the molecular
mechanisms underlying these effects remain unknown.

For this latest study, Swedish and US researchers demonstrated
that the allicin molecule in garlic stimulated sensory pain neurons
in rats by activating the TRPA1 channel.

The Allium family of plants produce organosulfur compounds, such
as allicin and diallyl disulfide (DADS), which account for their
pungency and spicy aroma.

"Intriguingly, allicin and DADS share structural similarities
with allyl isothiocyanate, the pungent ingredient in wasabi and
other mustard plants that induces pain and inflammation by
activating TRPA1, an excitatory ion channel on primary sensory
neurons of the pain pathway,"​ reports study co-author David
Julius, a professor of cellular and molecular pharmacology at the
University of California, San Francisco.

Suggesting a tentative link to the reported health benefits of
eating garlic, the scientists found that allicin and DADS induced
vasodilation (the healthy enlargement of blood vessels), by
activating "capsaicin-sensitive perivascular sensory nerve
endings."​

But still early days, research is now required in animals and
humans to advance the test-tube findings.

Allicin is converted to a variety of more stable sulfide
compounds over time or with heating, in correspondence with the
significantly milder taste of roasted garlic. And this active
compound is enjoying a certain growth, mostly in garlic
supplements, on the back of the reported health benefits.

Garlic supplements are worth more than $100 million in the US. A
garlic extract (supplied by UK firm Allimax) was recently added
into the formulation of new product from US functional drinks
company V-Net Beverage, thought to be the first time a garlic
extract has been added to a functional food.